A gas turbine engine generally includes, in serial flow order, a compressor section, a combustion section, a turbine section and an exhaust section. In operation, air enters an inlet of the compressor section where one or more axial compressors progressively compress the air until it reaches the combustion section. Fuel is mixed with the compressed air and burned within the combustion section to provide combustion gases. The combustion gases are routed from the combustion section through a hot gas path defined within the turbine section and then exhausted from the turbine section via the exhaust section.
In particular configurations, the turbine section includes, in serial flow order, a high pressure (HP) turbine and a low pressure (LP) turbine. The HP turbine and the LP turbine each include various rotatable turbine components such as turbine rotor blades, rotor disks and retainers, and various stationary turbine components such as stator vanes or nozzles, turbine shrouds and engine frames. The rotatable and the stationary turbine components at least partially define the hot gas path through the turbine section. As the combustion gases flow through the hot gas path, thermal energy is transferred from the combustion gases to the rotatable turbine components and the stationary turbine components.
In general, the HP turbine and LP turbine may additionally include shroud assemblies which further define the hot gas path. A clearance gap may be defined between the shroud of a shroud assembly and the rotatable turbine components of an associated stage of rotatable turbine components. The shroud is typically retained within the gas turbine engine by a shroud hanger, which in turn is coupled to various other components of the engine.
One issue with presently known shroud assemblies is the loads experienced by the shrouds during operation of the engine. Known “open” style shrouds include flanges at the forward and rear ends for coupling the shroud to the hanger. The flanges have axially extending bore holes defined herein, and pins are extended through the bore holes and mating components of the hanger to couple the shroud and hanger together. Because the flanges are on the forward and rear ends of the shroud, they are “pinched” between mating components of the hanger. This “pinching”, and the general orientation of the flanges, can cause increased loading experienced by the shrouds during operation. Further, thermal stresses can be experienced due to higher temperatures in the hot gas path travelling through these flanges to cooler areas outside of the hot gas path. Still further, leakages in the hot gas path seal that the shroud assemblies provide can occur. Such issues are of increased concern when the shrouds are formed from ceramic matrix composite materials.
Accordingly, improved shrouds and shroud assemblies for gas turbine engines are desired. For example, shrouds and shroud assemblies with improved apparatus for coupling the shrouds to hangers of the shroud assemblies, and which reduce loading issues, thermal stress issues, and leakage issues, would be advantageous.